a cell

[lohita]

a cell is in a solution of red dye. it is being abserved through a microscope. first, the cytoplasm of cell turns into pick and then it slowly becomes clear. cell cannot metabolise red dye. so what is actually happening here? why does it turn pick and then it is clear?

[MrMistery]

I don't know what pick is. But i suppose it is a color similar to red. Ok, so how i see it:
Macromolecules(except celulose) enter the cell through endocitosys. The cell does not know what it is "eating" when it does this. That is why different poisons kill the cell. There are 2 possibilities:
1. The dye is harmful to the cell, it kills it
2. The dye is harmless but also useless to the cell because it can not methabolise it. So the dye is excreted through deferrent methods(depends on the cell type) but always through exocitosys. Then the citoplasm turns clear again
Hope this helps
Regards,
Andrew

[lohita]

but my teacher has said that it is something to do with active and passive transportations

[mith]

That's basically what Andrew described in possibility 2. By diffusion the red dye seeps into the cell because the cell has no red dye(Like water flowing down a stream). The cell pumps the red dye back out.

[MrMistery]

Mithril is right. Paint firstly goes into the cell through passive transport. Whether this is simple diffusion or endocitosys i do not know, it depends on the chemical formula of the paint molecule. I tend to think it is too big so it will have to go through endocitosys.
Now the cell gets rid of the paint through exocitosys. I don't know exactly how that works, all I know it is active transport. I am studying it now